Recently, batteries having a small size, a light weight, a long life and a high energy density are particularly demanded as a power source for small-size electronic equipments with the rapid advance of electronics. In this connection, non-aqueous electrolyte primary batteries such as lithium primary battery using manganese dioxide as a positive electrode and lithium as a negative electrode and the like are known as a battery having a high energy density because an electrode potential of lithium is lowest among metals and an electric capacity per unit volume is large, and there are actively studies many kinds thereof. On the other hand, there are developed run-flat tires capable of continuously running over a significant distance up to a repair-makeup place even if a pneumatic tire is punctured or the like. As a result, it is proposed to provide the run-flat tire with an internal pressure alarm device of sending an abnormality transmitting signal when the internal pressure of the tire measured is rendered into an internal pressure lower than the given value. As a power source for the internal pressure alarm device is used the above non-aqueous electrolyte primary battery having a small size, a light weight, a long life and a high energy density and using manganese dioxide as a positive electrode and lithium as a negative electrode.
In the above non-aqueous electrolyte primary battery, lithium is frequently used as a material forming the negative electrode. Since lithium violently reacts with a compound having an active proton such as water, alcohol or the like, an electrolyte to be used is limited to a non-aqueous solution or a solid electrolyte. The solid electrolyte is limited to only a use under a low discharge current because an ionic conductivity is low. Therefore, the electrolyte usually used is an aprotic organic solvent such as an ester-based organic solvent or the like at the present time.
On the other hand, a nickel-cadmium battery has been prevailingly used as a secondary battery for memory back-up of AV-information equipments such as personal computer, VTR and the like or a driving power source therefor. Recently, non-aqueous electrolyte batteries (metallic lithium secondary battery, lithium ion secondary battery and the like) are particularly noted as an alternative for the nickel-cadmium battery because they have a high voltage and a high energy density and indicate an excellent self-discharge characteristic, and there are attempted various developments and a part of products is commercialized. For example, more than half of note-type personal computers, mobile phones are driven by the non-aqueous electrolyte secondary battery.
In these non-aqueous electrolyte secondary batteries, a lithium-containing composite oxide is used as a material forming the positive electrode, and carbon is frequently used as a material forming the negative electrode, while various organic solvents are used as an electrolyte for the purpose of reducing a risk when lithium is produced on the surface of the negative electrode and making a driving voltage high. Also, in the non-aqueous electrolyte secondary battery for a camera, an alkali metal (particularly lithium metal or lithium alloy) is used as a negative electrode material, so that an aprotic organic solvent such as ester-based organic solvent or the like is usually used as an electrolyte.